Apparatus for cleaning boiler tubes



Nov. 25, 1924. 1,516,880

M. K. BOWMAN APPARATUS FOR CLEANING BOILER TUBES Filed Oct. 21 1920 Patented Nov. 2:5, 192%.

UNITE SFATES PATENT OFFIE.

MARK K. BOWMAN, OF MON'ICLAIR, NEW JERSEY, A SSIGNOR, BY MESNE ASSIGN- MENTS, TO RICHARD L. SUYDAM, OF NEW YORK, N. Y.

APPARATUS FOR CLEANING BOILER TUBES.

Application filed October 21, 1920. Serial No. 418,360.

To all whom it may concern:

Be it known that I, MARK K. BOWMAN, a citizen of the United States, and resident of Montclair, in the county of Essex and State of New Jersey, have invented certain ing the accumulation ahead of it as it is propelled through the tube. The apparatus of my present invention is broadly of the same type as that of my Patent No. 1,325,

348, issued December 16, 1919 and of my copending application, Serial No. 397,574, filed July 20, 1920 and can be used in substantially the same relations as the devices of said patent and said application.

An object of the invention is to provide a tube cleaning projectile of the above type which shall be effective. in its action and inexpensive in its construction and which shall be susceptible of being formed in any sizes for use with tubes of any diameter, and

which shall be particularly useful in clean- ,ing tubes of the very smallest diameters.

A ccording to'oue feature of the invention, I employ identical generally rectangular spring metal plates to serve as scraper elements, each having an asymmetrically arranged polygonal aperture, all fitted over a rod of corresponding cross-section, the successive plates extending outwardly from the rod at relatively small angular intervals. According to another preferred feature of the invention, round sided eyelets fitting over the rod are'u'sed as spacers between successive plates.

Referring now to the drawings in which .is shown oneof lvarious possible embodiments of the several features of the invention,

Fig. 1 is a side elevation of a preferred form of tube cleaning projectile,

Fig. 2 is a perspective view thereof,

Fig. 3 is an end elevation thereof taken from the right end,

Fig. at is a detail view of the supporting rod and the nuts on the end thereof,

Fig. 5 is a plan view of the washer,

Fig. 6 is a plan view of a spacer member, and;

Fig. 7 is a view showing the respective angular positions of succcessive scraper plate elements.

Fig. 8 is a plan view of a modification.

The views are all shown on a scale substantially double that of the smallest projectile for actual use in order to. better disclose the details of the construction.

Referring now to the drawings, I have shown a projectile comprising a supporting rod'l preferably square in cross-section. having threaded ends 2 and 3 as shown for a purpose to be set forth hereinafter. Upon the rod are mounted a plurality of the identical sprim metal scraper elements best shown in Fig. l comprising each a plate 4 of spring metal having parallel sides 5 and 6 and scale attacking end edges in the form of arcs of a. circle ofa diameter equal to the length of the plate. Centrally of each plate and preferably asymmetrirally thereof, 1

whose ratio is 1 to 3. It will be understoodthat plates ll and I) are stamped in the same die as plates A and C, stampingsBaud l lying upon the obverse side as compared with stampings A and C. It will be understood that the plates are successively fitted over the rod 1 in the cycle of positions A, B,

C and D atequal angular intervals of 45.

, Any appropriate means may be employed 7 .although two contacting to space the scrapers.equidistantly from each other lengthwise of the rod, so that the operative faces 7 of the successive plates will lie substantially upon a helix as best shown in Fig. '2. For this purpose I prefer to employ ordinary eyelets of the type shown in Fig. 6. The eyelet, it will be understood, consists of a thin tube of metal collapsed in a die so as to assume the form of a sheet metal ring as best shown in Fig. 6.

By preference, four of the plates are placed in contact with each other at one end of the rod as shown at 11 in the end view of Fig. 3, no spacers being interposed. These plates are angularly displaced with respect to each other, one corresponding to each of the positions indicated in Fig. 7 so that in end view, these plates produce substantially the disk effect shown in Fig. 2%, although a single disk may be used, if desired. The same construction may be employed at the lefthand end of the device, plates at right angles to each other, as shown in Fig. 1, are preferably employed. A circular leather washer 15 somewhat larger in diameter than the length of the scraper plates is fitted over the threaded end 2 of the rod, and a similar cork washer 18 is interposed between the set of plates at the end 3 and the plate adjacent thereto, and nuts 13 and 14 are threaded respectively over said ends to maintain the entire projectile in assembled relation, the nuts being preferably locked in position by means not shown.

In operation, more particularly for clean ing the slime out of condenser tubes, the projectile is forced a short distance into one of the tubes, the end of nut 13 in advance and compressed air or other propelling fluid is admitted to the tube. The force of the fluid as in the case of my prior patent and application will be sufiicient to drive the device through even: a dirty tube with high velocity. In this action, the leather washer which is in advance will push before it any' loose mud or slime in the tube and the spring metal plates which are preferably of a length approximately equal to the diameter of the tube will effectively loosen any slime or mud or any accumulation of scale adhering to the walls. The mud, slime or scale is attacked by the edge 7 of the scraper plates, and since these edges are arranged at angular intervals about the rod, the entire interior surface of the tube will be cleaned. The cork washer 18 at the rear or trailing end of the projectile has a. peculiar clinging eflect with respect to the tube and effectively wipes the remaining mud or slime out of the tube, the air blast acting to remove any moisture remaining in the tube. Leather washers, it is found, have a tendency to allow mud or slime to slip by.

The same construction of projectile may the cork washer 18.

the tube,

confined in back of the same, will blow be-- be used in the same manner for cleaning boiler tubes, but I prefer in this case to omit In this event, as the advanced leather washer 15 emerges from the current of air being no longer tweenthe plates and the projectile will thus be delivered from the end of the tube at low speed.

If desired, the projectile may be used for cleaning boiler tubes, the end carrying the leather washer being at the rear or trailing end. In this operation the leather washer 15 which is of somewhat larger diameter than the tube will becdme cupped and will thus wipe the inner surface ofthe tube.

It will be seen that by my construction the scraper elements are directly secured to the central supporting rod by direct contact therewith, a firm hold against relative ,rotation being effected by reason of the noncircular cross-section of the rod and the correspondingly shaped apertures or holding edges inthe scraper plates. It is, therefore,

apparent that I can provide a projectile adapted. for tubes of smaller diameter than f 3 would be possible in a case in which separate. sleeves or other elements would be required to mount the scraper elements upon the supporting rod.

It will be seen that my present invention provides a construction which is particularly inexpensive in that the scraper elements are all made of identical spring metal I stampings so that only one die and one operation is necessary to producetheni and the spacers are formed by simply collapsing eyelets of appropriate size and of any ordinary or standard construction. The assembly of the device can be easily and quickly 7 effected by unskilled labor and without the use of special tools.

In the preferred form of my invention,

the plates are at angles of 45 with respect to each other, that is, at angles of one half the degree angle subtended at the center of the square aperture 8 by each of the sides thereof. Similarly if a regular hexagonal rod were employed, the successive plates could be arranged at angles of 30 de rees with respect to each other, or one ha? the 60 degree angle subtended at the center of the hexagonal aperture by one of the sides thereof. It will be apparent that the same general relation would hold in any case where a rod is employed having a regular polygonal cross-section, and where the fof correspondingly shaped aperture in each plate 18 disposed asymmetrically thereof,

the sides of the aperture at the vertex there of adjacent the side of the plate being preferably at anglesrelative to the length of the plate having a ratio of 1 to 3, in the same -manner as in the case of the square aperture as described above.

no I

,45 being parallel to each struction, I provide double the scraping Thus, it will be seen that although only a single die need be used in makin all of the plates, yet by providing the pi apertures in the plates in the asymmetrical position shown, the angle between successive plates will be less than the angle between successive sides of the polygonal rod. Therefore, there is an effective peripheral distribution of the scale attacking edges and,

a projectile of short length will be adequate. Such short projectile can turn corners in the tubes to be cleaned with great facility.

Where two or more plates are angularly disposed in direct contact with. respect to each other intermediate theends-offthe pro-' e observed, he presence the tubesi El-Qc eyelets H over,,have rounded edges to "assurei'a gradual curvature of the operating plates as they encounted obstacles in passing through the tubes.

A desirable alterna iv H e form of scraper element .is shown; inv FigfiS. This. element is in the shape of. a Greek cross as would result from superposing two of the plates of 'Fig. 7 at right angles to each other. The sides of the square opening 8 being at angles of 22%'and-67 wlth respect to the sides of the cross, it is apparent from the foregoing that the axes of'eaich, plate could be mounted to extend at angles of 45 degrees with respect to those of the preceding and the succeeding plates,"the axes of a ternate plates other. By this conedge length for a given length of projectile as compared with the form of- Fig. 7 and the device is thereby rendered mechanically stronger and more effective in operation' I claim: 4 v

1. A tube cleaning projectile of the class described, comprising in combination, a rod, a plurality of scraper elements encircling said rod, said rod and elements being constructed and arranged to prevent rotation ygonal I having a non-circular cross-section the projectile may a width \plate, having a plates may be of said elements about said rod, and spacer elements between successive scraper elements, each said spacer element comprising a hollow annular metal member.

2. A tube cleaning projectile of the class described, comprising in combination, a rod a plurality of scraperelements having holding eyes snugly fitted about said rod to prevent rota.- tion of said elements with respect to said rod and ring shaped members substantially circular in cross-section encircling said rod and serving to space said scraper elements equidistantly from each other.

3. A. tube cleaning projectile of the class described, comprising in combination, a rod, aplurality of identical scraper plates fixed thereon, to extend at equal angular intervals, means spacing said' plates equidistantly and a plurality of said plates fixed near one end of the projectile in direct contact with each other ,and at said angular intervals, substantially disk-like structure. 4. Avtube cleaning projectile of the class described, comprisin in combination, a rod having a regular po ygonal cross'section, a plurality of identicalscraper plates having snaller than the length thereof, each plate having an aperture at its center of the same size and shap as the cross-secplurality of identical scraper plates having a width smaller than the length thereof, each plate having an aperture at its center of the same size and shape as the cross-section of said rod, the sides of said aperture being at angles relative to the length of the ratio of 1 to 3, whereby said fitted over said rod at equal angular intervals in a number of directions equal to the number of sides of the polygon..

Signed at New York, in the county of New York and State of New. York, this 19th day of October, A. D. 1920.

, MARK K. BOWMAN.

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